Process of indigo dyeing.



UNITED STATES HERMANN MULLER, OF PARIS, FRANCE.

PROCESS OF INDIGO DYEING.

' Specification of Letters Patent.

Patented Dec. 26, 1905.

Application filed April 2,1904:- Serial N0. 201,311.

To all whom it may concern:

Be it known that I, HERMANN MULLER, a subject of the Grand Duke ofBaden, residing at 2 Passage Violet, Paris, in the Republic of France,have invented certain new and useful Improvements in Indigo Dyeing, ofwhich the following is a full, clear, and exact description.

This invention is designed to facilitate and simplify the dyeing withindigo of textile fabrics either in the piece or yarn, to reduce thetime necessary for the preparation of the bath, and to effectconsiderable economy in the process of dyeing. The invention may beapplied to the dyeing of cotton, wool, silk, linen, or unions of thesefibers.

Hitherto in the process of indigo dyeing the preparation of the bathoccupied about from five to six days, and in the dyeing of cotton orother cloth it was considered necessary to dip the cloth or materialfour or five times into the vat to obtain a dark color. By my presentprocess I am able to prepare the bath in from three to four hours anduse it immediatel y after preparation and to dye to an equal shade in asingle operation. The old vats are dispensed with and I employ a Jiggeror Foulard machine or other suitable form of dyeing-rnachine withrollers or cylinders.

My invention consists, essentially, in the preparation of a dye-bathfrom indigo (natural or artificial) with the addition or combination ofone or more of the following materials: stannous oxid, (SnO.) stannicoxid, (SnO2,) hydrated stannous oxid, SD20 (OHh, hydrated stannic oxid,(HQSnO acetic acid, caustic soda in solution, chromate of potash, andhydrochloric acid.

According as the material to be dyed is cotton, wool, or silk, it isnecessary to proceed differently and to use dye-baths of differentcomposition. I

Good results in the dyeing of cotton are obtained from a dye-bathprepared as follows: fifty grams powdered indigo made into a paste andboiled with one hundred and fifty cubic centimeters stannic oxid (SHOZ)dissolves in acetic acid, forming an acetate of tin 20 to I/Vhen theacetic acid is nearly evaporated, into this is poured slowly and mixedfour hundred and fifty cubic centimeters caustic soda in solution, 40Baum, and boiled until the indigo is dissolved. Add three hundred andfifty cubic centimeters water, boil again, and strain the solutionthrough a metal sieve. The solution will be of a yellow color, and thematerials to be dyed are passed through it (the bath may be either coldor hot) for about ten to fifteen seconds, then wellsqueezed out andslightly aired, and subsequently passed into a bath for one-half to oneminute of two grams bichromate of potash, one liter water, twenty-fivecubic centimeters hydrochloric acid. The material on removal is washed,soaped, rinsed, and dried.

Good results in the dyeing of wool and silk materials are obtained froma dye-bath prepared as follows: fifty parts powdered indigo made into apaste and heated with two hundred parts acetic acid, ninety per cent.Add two hundred parts stannic oxid, (SnOz.) The whole is boiled and justsuflicient causticsoda in solution added to dissolve and reduce theindigo, then boiled, and brought up to one thousand parts by addition ofwater thereto. The materials are passed for about fifteen to twentyseconds into this hot bath, then slightly aired, and passed through acold bath of a fixing solution. preferably containing two gramsbichromate of potash, one liter water, twentyfive cubic centimetershydrochloric acid.

Instead of using stannic oxid (SnO2) to form an acetate of tin for thepreparation of the dye-bath one can use equally as well other oxids oftin-such as stannous oxid, (SnO,) hydrated stannic oxid, (H2SnO3,) orhydrated stannous oxid, (Sn2O(OH)2.) Also the solution of caustic sodacan be replaced by a solution of caustic potash and the bichromate ofpotash by any other soluble chromate.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The process of dyeing fabrics and analogous materials which consistsin feeding the material through a dyeing-machine having adye-receptacle, subjecting it to a dye-bath composed of indigo, an oxidof tin, an acid and an alkaline solution, then airing said material, andfinally treating it with a fixing solution.

2. The process of dyeing fabrics and analogous materials which consistsin feeding the material through a dyeing-machine having a In Witnesswhereof I subscribe my signa cly ereceptacle,1 subjectingd it to aclye-batdh ture in presence of two Witnesses.

composed of inc igo, an oxi of tin, acetic aci and an alkaline solution,then airing said ma- HERMANN MULLER serial, and finally treating it witha solution \Vitnesses:

of bichromate of potassium and hydrochloric HANSON C COKE,

acid" 1 JOHN BARKER.

